Alternating-current magnetic apparatus.



PATENTED DELLA, 1906.

N 0 S R A L D ALTERNATING CURRENT MAGNETIC APPARATUS.

APPLIUATION FILED NOV. 22. 1905.

.INVEN'TOR WITNESSES:

ATTORNEY UNITED STATES PATENT OFFICE.

DAVID LARSON, or YONKERS, NEW YORK.

Specification of Letters Patent.

Patented Dec. 4, 1906.

Application filed November 22, 1906. Serial No. 288.511.

To all whom it may concern.

Be it known that 1, DAVID LARSON, a subject of the King of Sweden, and a resident of the city of Yonkers, Westchester county, New York State, have invented certain new and useful Improvements in Alternating- Current Magnetic Apparatus, of which the following is 'a specification.

My invention-relates to electromagnetic apparatus for use in conjunction with alternating intermittent or pulsating currents; and its object is to provide simple and eflicient apparatus of this kind which will be free from the chattering noise which is usually found in alternating-current apparatus and which will have other advantages which will be ointed out hereinafter.

Iwil now describe my invention in the following specification and point out the novel features thereof in claims.

Referring to the drawings, Figure l represents in side elevation an electromagnetic apparatus constructed according to my inven tion and .connected to actuate a brake. Fig. 2 represents in side elevation, partly in section, a modification ofmy invention, connectedin this case to operate a circuitcloser.

Like characters of reference represent corresponding parts in both figures.

1.0 designates an electromagnet which comprises a frame 11, preferably constructed of laminated magnetic material. This frame has two pole-pieces 12 and 13, between which a rotatable armature 14 is placed. This armature is pivoted at' 15 to a bracket 16, which is a partof a frame which supports the magnet-frame 11. This armature-14 is also preferably constructed of laminated mag netic material. Upon pole-piece 12 is a winding 17, and upon pole-piece 13 is a winding 18.

2-0 and 21 designate mains from a suitable source of electrical supply which, after passing through a transformer 22, may be connected to the windings. 17 and 18 or disconnected from these windings by a manually operated circuit-closer 23.

designates a brake-pulley rigidly mounted upon a shaft 31 and iartially surrounded by a brake-strap 32. T iis brakcstrap may be connected, as shown at 33 and 34, to a brake-lever 35, which is pivoted at '36 between the points 33 and 34. An adjustable weight 37 may be provided uponthe brakelever 35. Brake-lever 35 may be connected to-a short crank-arm 19, which is rigidly attached to the pivot'15'of armature 14,- and the lever is arranged. to move with the arma ture 14 by means of a connecting-rod 38. A spring 39 may also be provided for the purposeof cooperating with weight 37 in applylngthe brake strap 32 to the brake-pulley 30 This spring 39 bears u on the lower part of magnet-frame 11 and upon a collar. 38, which is mounted upon connecting-rod 38 and the position of which may be adjusted by means of a nut 38 to adjust the pressure of spring 39 upon brake-lever 35 A stoppiece 1 9 may be provided upon bracket 16 of the electromagnet to stop the movement of the short arm 19 in one direction.

j In Fig. 2 the frame 11 0f the 'electromag net is made in a different form, as is also its armature 14. In this case the magnetfrarn'e" is substantially of the form of the letter E with the three projecting portions forming magnetic poles. Upon the center of these projecting portions 12 a winding 17 is provided. The armature 14 in this case is arranged to have a vertical movement. When the magnet is not energized, this armature 14 is arranged to rest upon two projec-- tions 41 41, which are integral portions of a metallic frame 40, which may be arranged to hold the magnetic frame 11 together and also to support the various other parts of the apparatus, which I will now describe. Levers 42 42, which are pivoted at 42 42. are-connected together b two connecting-levers 43, which are pivotal y attached to levers 42 42 at 43 43 and which are pivotally connected together and to a connectingrod 44 at 44. This connecting-rod is connected at 14 to the armature 14. The lower ends of levers 42 42 carry upon them insulated contacts 45 '45. Springs 46 46 may be arranged to bear against the pivoted arms or levers 42 42, and their tension may be adjusted by means of adjustable stops 46 46, which are screwed ,intoa portion of. the frame 40. The lower ends 47 47 of frame 40 are insulated from the rest of the frame, as shown at 47 47 and arranged to carry contacts 48 '48. These contacts may be rigidly connected to the portions 47 47; but I prefer to provide springs 48 48 between the contacts and theirsupports, so that the contacts may have a resilient support.

jReferring now to Fig; 1, I will desc ribeQthej.

Operation of this device: When the magnet is not energized, the various parts arein the relative positions in which they are shown in the drawings, with the weight 37 and spring 39 through their connected mechanism ap' plying the brake-strap 32 to the brake-pulley 30. It may be seen that when the arts are in this position the mechanical wor i, which is accomplished by wei ht 37 and spring 39 and which is controlled by electromagnet 10,

tion as to include as many of the magneticlines as possible and in so doing it will move the crank-arm 19 to the left and through connecting-rod 38 will compress spring 39 and raise brake-lever: 35 and weight 37. This releases the brake-stra 32 from the brake-pulley 30. It is desira le to stop the -movement of the crank-arm 19 before it reachesa vertical position, so that when the magnetis' denergized the load upon the arm causes it to return to its original position and for this purpose the stop 19 is provided. It may be seen that during this operation above described the pivoted armature 14 will be moved into a state of magnetic equilibrium and will come to rest at apoint where the magnetic attraction and mechanical forces, which act upon this magnet 14, balance each other. The magnetic pull will gradually decrease as magnet 14 comes to the state of equilibrium, and with the parts arranged as described the mechanical pull upon connecting-rod 38, which is connected to magnet 14 in the manner described, will also decrease during this movement of magnet 14. An-

other eflect of this arrangement is that as armature 14 moves into a vertical position between poles 12 and 13 and includes more and more of the magnetic lines it will short-circuit these magnetic lines and have a choking effect upon the current passing through windings 17 and 18'. This, of course, will reduce the current in these windings after they have done their work, and with the parts as arranged the load upon the armature will itself be decreased at the same time. This will alstate of equilibrium between thepoles 12 and 13 in nearly the same position that it would take if it were not arranged to do any outside mechanical work. The effect of this is to decrease any possibility of noise in the various as it is in other apparatus of this character, it

would tend to increase the vibrations of the parts due to current fluctuations in the magnet. When the circuit-closer 23 is opened and current is thereby cut oil from the windings 17 and 18,-the various parts will return to the positions in which they are shown in the drawings, andthe' brake-strap 32 will again be applied to brake-pulley 30 with a maximum pressure.

The 0 eration of the device shown in Fig. 2 is simiiiir; When. circuit-closer 23 is closed, so that a current passes through winding 17 and energizes magnet-frame 1 1, the armature 14 will be attracted thereby and will move vertically upward until it reaches a state of magnetic equilibrium. The effect of this upward movement will be to move the levers 43 44 and their connected levers 42 42 into the positions shown by dotted lines. These levers form a toggle, and it may be seen that the'eflect of the load, which in this case is the weight of armature 14, and the pressure of springs 46 46 will be decreased during this movement, for as soon as the point 44 has been raised above the level of pivots 43 43 the springs 46 46 assist in supporting the weight of armature 14. The magnet-armature when in its raised position is preferably arranged to come to a state oi equilibrium without being in contact with any of the parts, so that all chattering noise due to current alternations is obviated. The levers 42 42 may be connected to move any desired mechanismfor example, to close contacts 45 45 against contacts 48 48, and to thereby close a circuit from the conductor 50 through a circuit 51 and to a conductor 52. The pressure of springs 46 46 should be so adjusted that when circuit-closer 23 is opened 'the weight of armature 14 will be sul'licient to compress these springs and allow the parts to resume their original positions. In this arrangement, as in the one previously described, the armature when it comes to a state of equilibrium will be in position to short-circuit the magnetic lines in magnetframe 11, and will therefore cut down the current consumption in'winding 17. As has already been'seen, the mechanical load upon armature 14 in this case is not only released from the armature 14, but is so mature of laminated oted movable shifted 'as to support the armature 14.

through the toggle-joint arrangementof the,

levers.

I have shown that this invention-is applicable to several forms of apparatus; but it is by no means scribed.

It is believed that the combination herein shown for gradually reducing the load which is moved or carried by an electromagnetic armature, which is attracted by magnetic lines into a state of equilibrium, wherethe magnetic efiect will be such that when the armature has reached such a condition the load will have been removed from it, is new. The mechanical connections herein shown and described are such that when the magnet is deenergized and the parts are'returned to their original position "the efiective load which the magnet controls will again be increased to its maximum.

This invention not only accomplishes the above results, but also increases the efii ciency of alternatin current magnets and does away with the chattering noises usually found in ap )aratus of this kind.

What I claim is 1. A source of alternating-current su ply, a winding energized thereby, a movable body of laminated inductive material, a load upon said movable body, means dependent upon the current in the winding for magnetically attracting and balancing the body, and means for reducing the load upon said body as the body is moved.

' 2. A source of alternating-current supply, a winding energized thereby, an armature of laminated magnetic material pivoted in the field of said winding and rotatable thereby to a position of magnetic equilibrium, a load connected to said armature and means for reducing the load as the armature is rotated.

3. A source of alternating-current supply,

two windings energized thereby, an armature pivoted between said windings and rotatable on the pivot to a position of magnetic equilibrium between said windings, a load for the armature, and intermediate mechanism connecting the load and the armature and arranged to reduce the eiiect of the load upon the armature as the armature is rotated.

4. An alternating-current magnet; an armagnetic' material therefor, a load for the armature, said armature being arranged to be brought into a state "of magnetic equilibrium between the pull of the magnet and. the load and means for reducing the ellect ot the load upon the armature as the armature is brought into the state of equilibrium.

5. An alternating-current magnet, a pivarmature of laminated magnetic material therefor, a spring arranged to act upon the armature, said armature arlimited to those herein 'deequilibrium thereby,

ranged to be brought into a state of magnetic equilibriumbetween the pull of the. magnet and the action of the spring, and means for reducing the effect of the spring on the armature as the armature is moved.

6. An alternating-current magnet, an armature of laminated magnetic material arranged to bemoved into a state of magnetic equilibrium thereby, means for mechanically opposing the pull of the magnet, said means being arrangedto have less opposition efiect to the pull ofthe magnet after thearmature has been moved by the magnet.

7. An alternating-current magnet, an armature of laminated magnetic material arranged to be moved into a state of magnetic equilibrium thereby, means for mechanically opposing the pull of the magnet, said means being arranged to have its opposition efl ect to the pull of the magnet reduced from a maximum to a minimum during the movement of the armature. 7

8. An alternating-current magnet,

mature of laminated magnetic material ar ranged to be moved equilibrium thereby, carried by. the armature, and means for re ducing said load sothat butpart of it is car ried by the armature after the armature has been moved by the magnet.

9. An alternating-current magnet, an armature of laminated magnetic material arranged to be moved into a state of magnetic a load connected to and into a state of magnetic a load connected to and a carried by the armature, and means for rc-.

ducing said load from a maximum to a mini mum as the armature is moved by the mag- I net.

10. An alternatingcurrent magnet, an armature arranged to be moved into a state of magnetic equilibrium thereby, a load for the armature, intermediate mechanism connecting the load to the armature and arranged to diminish. the eiiect of the load upon the armature as the armature is moved by the magnet. I

11. An alternating-current magnet, an armature arranged to be moved intoa state of magnetic equilibrium thereby, a load for the armature, intermediate mechanism connectmg the load to the armature, and arranged to gradually diminish. the effect of the load upon the armature as the armature is moved.

12. An alternating-current magnet, a piv-. oted armature of laminated magnetic materialv arranged to be moved into a state of magnetic equilibrium thereby, an adjustable load for the armature, connections upon the load and the armature arranged to diminish the effect of the load upon the armature as the armature is moved by the magnet.

13. An alternating-current magnet, a pivoted armature arranged to be moved into a state of magnetic equilibrium thereby, a load for the armature, a crank-arm and a connect' ing-rod arranged to connect the load to the armature,. said crank-arm and connectingrod being arranged to diminishthe effect,

ture constructedof laminated magnetic material, a load for the armature, intermediate mechanism connecting the load'to the armature and arranged to diminish the effect of the load upon the armature as the armature is moved by the magnet.

15.. An alternating-current magnet, frames for said magnet, a laminated. core between said frames having two pole-pieces, windings on said pole-pieces, an armature between said pole-pieces, a pivot for the armature supported by said frames, aload for the armature, intermediate mechanism connecting the load to the armature, said core being arranged to rotate the armature intoa state of magnetic equilibrium. and said intermediate mechanism being arranged to diminish the effect of the load upon the armature when the armature is rotated. v

16. An alternating-curren t magnet, a winding therefor, a source of single-phase alternating-current supply, means for connecting said winding to the source of supply, an armature of laminated magnetic material arranged to be moved into a state of equilibrium by the magnet and means for mechanically opposing the pull of the magnet, said means being arranged to have less opposition effect to the pull of the magnet after the armature has been moved by the magnet.

17. An alternating-current magnet, a winding therefor, a source of single-phase alterating-current supply, means for connecting and disconnecting said-winding to and from the source of supply, an armature of. laminated magnetic material arranged to be moved by the magnet into a state of magnetic equilibrium, an adjustable load for the armature, intermediate mechanism connecting the load to the armature and arrangedto diminish the effect of the load fu on the =armature as the armature is moved ythe magnet.

18. An alternating current magnet constructed of laminated magnetic material, a winding therefor, a source of single-phase alternating-current supply, means for connecting and disconnecting said Winding to' and from sa1d source of supply, an-armature arranged to be moved by t e ma net into a state of magnetic-equilibrium, sai armature being constructed of laminated magnetic material, an adjustable spring arranged to resist the pull of the armature, intermediate mechanism connecting the spring to the'armature and arranged to diminish the effect of the spring upon the armature as the armature is moved by the magnet.

195An alternating current magnet con structed of laminated magnetic material, a windingtherefor, a source of single-phase alternating-current supply, means for connecting and disconnecting said winding to and from said source of supply, an armature being arranged to reduce the current in the winding after it has been moved by the magnet.

207 An alternatin -current magnet, an ar mature of laminated magnetic material arranged to be moved into a state of magnetic equilibrium thereby, a load connected to and carried "by the armature, and means for reducing saidload so thatbut part of it is carried by the armature after the armature has been moved by the magnet, and for increasing the load to a maximum after the arma ture has been released by the magnet.

21. An alternating-current magnet, an armature arranged to be moved into a state of magnetic equilibrium thereby, a load for the armature, a crank-arm and connecting-rod connecting the load to the armature, said crank-arm and connecting-rod being arranged to reduce said load so that but part of it is carried by the armature after the armature has been moved by the ma net, and a stop for limiting the movement of the crankarm.

22. An alternatingcurrent magnet constructed of laminated magnetic material, an armature arranged to be moved into a state of ma netic equilibrium thereby, said armature a so constructed of laminated magnetic material, a winding for the magnet, a current-supply for the winding, an adjustable spring connected to and opposing the movement of the armature, and means for reducing the opposing effect of the spring through the movement of the armature after the armature has been moved by the magnet.

23. An alternating-current magnet constructed of laminated magnetic material, an armaturearranged to be moved into a state of ma netic equilibrium thereby, said armature a so constructed of laminated magnetic material, a winding for the magnet, a current supply for the winding, an adjustable spring connected to and opposing the movement of the armature, means for reducing the opposing eflect of the spring through the moVe- I I .In testimony whereof I have signed my ment of the armature after the armature has name to this specification in the presence of been moved by the magnet, said magnet and two subscribing Witnesses.

armature being arranged to automatieallyre- DAVID LARSON. (luce the current in the winding whe'n their Witnesses: relative position is changed by the movement ALFRED C. BEoHET,

of the armature. 1 ER EST. W. MARSHALL. 

